Thread-take-up mechanism for sewing-machines.



w. R. BLAIR. THREAD TAKE-UP MECHANISM FOR SEWING MACHINES.APPLIUATION-IILED JAN. 25 1912.

1,048,442. v. Batgnted Dec. 24', 1912.

WITNESSES." IN VE/V TOR v [UNITED S '1ATES PATENT OFFICE.

WILLIAM BLAIR, OF ST. LOUIS, MISSOURI, ASSIGNOR TO L. .NDIS MACHINECOMPANY, OF ST. LOUIS,

MISSOURI A CORPORATION OF MISSOURI.

THREAD-TAKE-UP MECHANISM FOR SEWING-MAGHINES.

Specification of Letters Patent.

Patented Dec. 24,1912.

Application filed January 25, 1912. Serial No. 673,400.

To all whom it may concern Be it known that I, NVILLIAM R, BLAIR, a

citizen of the United States, residing at St.

in the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, forming part of thisspecification, in which-' igure 1 is a side elevational view of myimproved thread .take-up mechanisms for sewing machines. Fig. 2 is avertical sectional view on line 2 2, Fig. 1. Fig. 3 is a sideelevational view showing the parts in different position. from thatdisclosed in Fig. 1.

This invention relates to a new and useful improvement in thread take-upmechanisms for sewing machines particularly of the waxed thread typeused for sewing leather and consists in the peculiar arrangement of apivoted thread lever, a floating lever and means for driving the same,together with the connections between said lever and the movable take-uprollers, all of which are hereinafter to be described, and afterwardpointed out in the claims.

-In the drawings: 1 indicates the main frame or housing of the sewingmachine to which is secured, a bracket 2, upon which bracket is pivotedthe thread lever 3', the pivot point of said lever being indicated at3?. The. outer end of lever 3 is provided with a roller 4 over which athread 5 passes to the stitch forming mechanism. The inner end of lever3 is connected by a link 6 to a curved slotted rock arm 7, said armbeing mounted upon a rock shaft 8, whereby the arm 7 vibrates in theoperation of the machine. The link 6 above referred to is pivotallyconnected at 6 to a floating lever 9 The inner end of said lever isslotted as at 11 to cooperate with a pin 10 mounted in the housing ofthe machine, this slot and pin connection or mounting permitting saidfloating lever to fulcrum. This variable fulcrum is necessary, when itdesired to adjust the connection between the link 6 and the rock arm 7.rock arm is preferably curved in an arc of a circle described from theaxis of the pivotal connection between link 6 and the thread and thethread is being ing the take-up thereof, and

The slot in the end of the' mal position, as shown in full lines Fig. 1,the connection between link (i and the rocking lever 7 may be adjustedoutwardly, as indicated by dotted lines in Fig. 1, such adjustment notdisturbing the position of any of the parts which would affect thestraight lines assumed by the thread in its feeding action. However,when the lever 7 descends taken up, the thread lever, when the link 6adjusted outwardly in the slot of the rock arm 7, as indicated by dottedlines in l ig. 3, islcaused to make a greater stroke, as is also thefloating lever 9 and the parts controlled thereby.

9 before referred to is The floating lever pivotally connected at itsforward end to a Y-shaped oscillating lever 12, which carries the tworollers 13 one-on eachprong, and which lever is guided in itsoscillatory movement by means of a headed stud 14 operating in aT-shapedgroove in the face of a bracket 15, (see Fig. 2,) secured to theframe or housing of the machine.

In operation, the thread 5 leads from a wax pot through an eye 2 in thebracket 2, then through an eye 3 on the inner end of lever 3, thencefrom a roller 16 mounted on bracket 2 and through an eye 3 on the innerend-of the thread lever 23. After passing through this eye 3 the threadpasses between clamping or looking jaws 17 and 18, which are operated tolock the thread durt-o, release the is being fed to the but as theseclamppart of my presentinventhread when the same stitch forming machine,ing jaws form no tion, I shall not describe them more fully here. Fromthe clamping jaws the thread passes through an eye in a post 2 on thebracket- 2 thence under one of the rollers 13 on the oscillatingY-sha'ped lever through an eye in a stationary post 19, thence under thecompanion roller 13 on the Y-shaped oscillating lever, and finally overthe roller 4 of the thread lever 3 to the stitch forming mechanism. a I

, When the rocking lever 7 moves from the position shown in Fig.1 to theposition shown in Fig. 3, the thread lever is directly operated therebyand consequently the dislever 3, whereby when the parts are in noryfor-each vibration, will determine the stroke of the thread lever. Thecloser the axis of movement of said pivotal connection is to the shaft8, the shorter Will be the movement of the thread lever, this movementincreasing as the link is adjusted outwardly in its slot. I

The floating lever with its variable fulcrum is carried with the link 6in the'dil'l'erent positions of the latter, and this Will tend to tiltthe Y-shaped oscillating lever slightly on its vertically sliding pivotpin, but this is not objectionable in practice. As the link (5 is adjusied outwardly on'the rock arm 7, its stroke becomes greater, due tothe grealer arc of movement of its co-actin (hiring member, and hencethe forward en of the floating lever under such conditions, will begiven a 'relativel greater stroke shown by dotted lines in Fig. 3. I y

I claim:

1. In a thread takeup mechanism for sewing a rock arm,

machines, the combination of a thread lever a rock arm, a linkconnecting said thread lever and rock arm, a floating ever having avariable fulcrum and con- --nected to said link,

and an oscillatory thread lever to which the outer end of said floatinglever is connect-ed.

In a device of the class described, a pivoted thread lever, anoscillatory thread lever, a floating lever pivoted to said oscillatonythread lever, a. link connected to said pivoted thread 1e erand saidfloating lever,

and art-adjustable connect" n' between said link and'said rock arm forregulating the throw of said thread levers. In testimony whereof Ihereunto aflix my signature in the presence of two witnesses. this 23dday of January,- 1912. v WILLIAM R. BLAIR. Witnesses: v i

F. R, CORNWALL, M. P. SMITH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

- Washington, D. c. i v

